Roller bit



Aug. 8, 1933. w. 1.. CHILDS ROLLER BIT Filed Deo. 12, 1931 n l Q Patented Aug. 8, 1933 UNITE SATB PATE ROLLER BIT William L. Childs, Houston, Tex., assigner to Reed Roller Bit Company, Houston, Tex., a Corporaj tion of Texas Application December l2, 1931. Serial No. 580,675

5 Claims.

.this type that will cut eiciently hard and soft formations.

The preferred embodiment of the invention is illustrated by the accompanying drawing, of which Fig. 1 is a sectional elevation of the bit; Fig. 2, a sectional elevation at substantially a right angle to Fig. 1; Fig. 3, a bottom plan view, and Fig. 4, a detail view of the cutter support.

The conventional cross roller bit embodies a pair of side roller cutters and about six cross roller cutters, the latter of which are necessarily small. And the side and cross roller cutters are in substantially the same horizontal plane. The present invention provides a roller bit having fewer and larger cross roller cutters that project below the side` roller cutters to cut in advance thereof.

In the drawing, the bit head is indicated at 1. It has a central opening 2 for the reception of the post of the cutter support, and water courses 3 through which water is discharged upon the cutters. Depending from the head, at substantially ninety degrees apart, are four bearing projections 4, 5, 6 and 7 having downwardly opening slots 8, 9, 10 and 1l, respectively. The inner walls 12, 13 and 14 of projections 4, 5 and 6 are.inclined upwardly and inwardly toward the longitudinal axis of the head. The inner wall l5 of projection 7 is substantially parallel with the longitudinal axis of the head.

The cutter support 16 has a central upwardly projecting post 17; a pair of side cutter pins 18 and 19 projecting upwardly and outwardly; a cross cutter pin 20 projecting upwardly and outwardly; and a cross cutter pir 21 projecting outwardly at substantially a right angle to the post.,

The post 17 is slidable in opening 2 in the head and is secured therein by a nut 22. The pins 18, 19, 20, and 21 are slidable in slots 8, 9, 10, and l1, respectively.

Upon the side cutter pins 18 and 19 are side roller cutters 23 and 24 that extend laterally from the periphery of the head. Upon the cross cutter pin 20 is a cross roller cutter 25. And upon cross cutter pin 21 are cross roller cutters 26 and 27.

The cross roller cutters 25, 26 and 27 project below the side roller cutters 23 and 24 to cut in advance thereof.' The cutting paths of the cross roller cutters and the side roller cutters are substantially equal to the transverse area of the head.

I claim:

1. A roller bit having a head, said head having a central opening and four depending projections at substantially ninety degrees apart, each'of said projections having therein a downwardly opening slot; a cutter support having a central post projecting upwardly, side cutter pins projecting upwardly and outwardly, a cross cutter pin projecting outwardly, and a cross cutter pin projecting upwardly and outwardly; said post being slidable in said opening and said pins in said slots; means to hold said post in said opening; a side roller cutter on each of said side cutter pins; a cross roller cutter on one of said cross cutter pins; and two cross roller cutters on the other of said cross cutter pins; said cross roller cutters projecting below said side roller cutters to cut in advance thereof; the cutting paths of said side roller cutters and cross roller cutters being substantially equal to the transverse area of said head.

2. A roller bit having a head; side roller cutcross roller cutter between said side roller cutters and rotatable on an axis inclined downwardly and inwardly toward the longitudinal axis of said head; and a pair of cross roller cutters between said side roller cutters and in substantially the same plane with said inclined cross roller cutter and rotatable on an axis at substantially a angle to the longitudinal axis of said head; said cross roller cutters projecting below' said side roller cutters to cut in advance thereof; the cutting paths of said side roller cutters and cross roller cutters being substantially equal to the transverse area of the head.

3. A bit head having four depending bearing projections substantially ninety degrees apart,

the inner walls of three of said bearing projections being inclined upwardly and inwardly toward the longitudinal axis of said head, and the inner wall of the other of said projections being substantially parallel witl` the longitudinal axis of said head.

4. A cutter support having a central post, side roller cutter pins projecting upwardly and outwardly from opposite sidesof said post, a cross roller cutter pin projecting upwardly and outwardly from said post, and a cross roller'cutterv no 2 pin projecting outwardly at substantially a ninety degree angle to said post.

5. A roller bit having a head; side roller cutters on opposite sides of said head rotatable onv axes inclined downwardly and inwardly toward the longitudinal axis of said head, and extending laterally beyond the periphery of said head; a cross roller cutter between said side roller eutters and rotatable on an axis inclined downward- 

